Directional control of missiles

ABSTRACT

A missile includes one or more arrays of barrel assemblies that are displaced from the centre of gravity of missile. Each barrel assembly includes a plurality of projectiles axially disposed within a barrel, and each projectile is associated with a discrete propellant charge for propelling the projectile sequentially from the barrel. Each array of barrel assemblies is capable of selectively firing the projectiles from selected barrels, whereby the missile is accelerated by the reactionary force generated by said firing of projectiles and the missile is deflected onto a new course or trajectory. This enables the missile to be steered to intercept its target, even if the target is undertaking evasive manoeuvres. Each barrel assembly may include multiple projectiles.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national phase application based onPCT/AU01/00607, filed May 25, 2001, the content of which is incorporatedherein by reference, and claims the priority of Australian PatentApplication No. PQ 7763, filed May 25, 2000, the content of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to directional control of missiles. Inparticular the present invention relates to missiles capable ofdirectional control and to a process of directionally controlling amissile.

2. Discussion of the Background Art

Missiles are objects that can be propelled or shot, towards a target.Missiles include a variety of objects, many of which will be applicableto the present invention. For example, missiles such as high altitudeballistic missiles or out of atmosphere ballistic missiles are widelyemployed as long-range strike weapons as they are very effective anddifficult to detect in time for adequate defences to be actioned. Highaltitude ballistic missiles may be required to make swift corrections toflight paths in order to avoid attack, such as from directionallycontrolled missiles.

Directionally controlled missiles that are employed to defend againstincoming missiles require pinpoint position accuracy in order tointercept an incoming missile that may be able to change its directionas a defence against the incoming missile. Even if defences are actionedearly, the size of the target and the relative approach speed of thedefensive missile makes any late correction of flight path difficult andlimits the chances of defensive missiles making a direct hit.Directionally controlled missiles may be required to make rapid changesto their flight paths in order to intercept their target.

Propelled missiles, such as ground-to-air, sea-to-air, air-to-air,ground-to-sea, air-to-sea, sea-to-sea, air-to-ground, sea-to-ground andground-to-ground, are also employed to attack targets that may makeevasive manoeuvers once the incoming threat has been identified.

Additionally, missiles that are propelled from a barrel by thedetonation of a propellant charge may be required to make rapiddirectional changes to ensure that they hit their targets.

SUMMARY OF THE INVENTION

We have now found a directional control system that may make rapidcorrections of flight path to divert a missile.

According to the present invention there is provided a missile includingan array of barrel assemblies, each barrel assembly having a pluralityof projectiles axially disposed within a barrel, which projectiles areassociated with discrete propellant charges for propelling saidprojectiles sequentially from the barrel, wherein said array of barrelassemblies is capable of selectively firing the projectiles fromselected barrels whereby said missile is accelerated by the reactionaryforce generated by said firing of projectiles.

In one embodiment of the invention the missile may be a powered missile,such as a rocket or jet powered missile, propelled in a controlledmanner towards its target. Such targets may by stationary or in motion.The present invention is particularly applicable to defensive missilestargeted onto the converging path of an incoming missile, such as a highaltitude or out-of-atmosphere ballistic missiles. The present inventionmay also be applied to in-atmosphere missiles that may advantageouslyhave aerofoils to aid lift in lift and/or stability.

The present invention is also applicable to missiles that are propelledfrom a barrel by the detonation of a propellant charge, such as highcaliber projectiles.

The present invention may take particular advantage of barrel assembliesof the type described in the present inventor's earlier InternationalPatent Application Nos. PCT/AU94/00124 and PCT/AU96/00459. Such barrelassemblies include a barrel, a plurality of projectiles axially disposedwithin the barrel for operative sealing engagement with the bore of thebarrel, and discrete propellant charges for propelling respectiveprojectiles sequentially through the muzzle of the barrel.

The overall shape of the projectile is not narrowly critical, as theprojectile is a mass against which the propellant acts and exerts areactionary force on the breech of the barrel. In the context of thepresent invention the breech may be formed by subsequent projectilesremaining in the barrel in sealing engagement with the bore of thebarrel. The reactionary force is transferred from the breech of thebarrel to the missile and results in an acceleration of the missile.

The projectiles may be conventionally shaped, dart-like, generallyspherical or any other convenient shape. The projectile may also includefins or aerofoils that may advantageously be offset to generate astabilising spin, and/or directional lift as the dart is propelled froma barrel that may be a smooth-bored barrel.

The projectile is propelled by a charge that may be located in apropellant space and may be formed as a solid block to assist in loadingthe barrel assemblies. Alternatively the propellant charge may beencased and may include an embedded primer having external contact meansadapted for contacting a pre-positioned electrical contact associatedwith the barrel. For example the primer could be provided with a sprungcontact which may be retracted to enable insertion of the cased chargeinto the barrel and to spring out into a barrel aperture upon alignmentwith that aperture for operative contact with its mating barrel contact.If desired the outer case may be consumable or may chemically assist thepropellant burn. Furthermore an assembly of stacked and bonded orseparate cased charges and projectiles may be provided to facilitate thereloading of a barrel.

The barrel may be non-metallic and the bore of the barrel may includerecesses that may fully or partly accommodate the ignition means. Inthis configuration the barrel may house electrical conductors whichfacilitate electrical communication between the control means andignition means. This configuration may be utilised for disposable barrelassemblies that have a limited firing life and the ignition means andcontrol wire or wires therefor can be integrally manufactured with thebarrel.

A barrel assembly may alternatively include ignition apertures in thebarrel and the ignition means are disposed outside the barrel andadjacent the apertures. The barrel may be surrounded by a non-metallicouter barrel which may include recesses adapted to accommodate theignition means. The outer barrel may also house electrical conductorswhich facilitate electrical communication between the control means andignition means. The outer barrel may be formed as a laminated plasticsbarrel which may include a printed circuit laminate for the ignitionmeans.

The electrical ignition for sequentially igniting the propellant chargesof a barrel assembly may preferably include the steps of igniting theleading propellant charge by sending an ignition signal through thestacked projectiles, and causing ignition of the leading propellantcharge to arm the next propellant charge for actuation by the nextignition signal. Suitably all propellant charges inwardly from the endof a loaded barrel are disarmed by the insertion of respectiveinsulating fuses disposed between normally closed electrical contacts.

Ignition of the propellant may be achieved electrically or ignition mayutilise conventional firing pin type methods such as by using acentre-fire primer igniting the outermost projectile and controlledconsequent ignition causing sequential ignition of the propellant chargeof subsequent rounds. This may be achieved by calculated reaction and/orcontrolled rearward leakage of combustion gases or controlled burning offuse columns extending through the projectiles or the barrel.

In another form the ignition is electronically controlled withrespective propellant charges being associated with primers which aretriggered by distinctive ignition signals. For example the primers inthe stacked propellant charges may be sequenced for increasing pulsewidth ignition requirements whereby electronic controls may selectivelysend ignition pulses of increasing pulse widths to ignite the propellantcharges sequentially in a selected time order. Preferably however thepropellant charges are ignited by a set pulse width signal and burningof the leading propellant charge arms the next propellant charge foractuation by the next emitted pulse.

Suitably in such embodiments all propellant charges inwardly from theend of a loaded barrel are disarmed by the insertion of respectiveinsulating fuses disposed between insertion of respective insulatingfuses disposed between normally closed electrical contacts, the fusesbeing set to burn to enable the contacts to close upon transmission of asuitable triggering signal and each insulating fuse being open to arespective leading propellant charge for ignition thereby.

A number of projectiles can be fired simultaneously from a plurality ofbarrels or in quick succession from the one barrel. In such arrangementsthe electrical signal may be carried externally of the barrel or it maybe carried through the superimposed projectiles which may clip on to oneanother to continue the electrical circuit through the barrel, or abutin electrical contact with one another. The projectiles may carry thecontrol circuit or they may form a circuit with the barrel.

The array of barrel assemblies may be disposed radially from the centerof mass of the missile. Such configurations are particularly suited tomissiles that do not incorporate a propulsion system. The firing ofprojectiles simply displaces the missile and the missile continues uponits trajectory, save for the displacement. Whilst radially disposedarrays of barrel assemblies may also be used to advantage in missilesincorporating propulsion systems, arrays of barrel assemblies thatgenerate a moment, or turning force, on the missile are particularlypreferred. The rapid turning of the missile by the firing of theprojectiles permits the attitude of the missile to be controlled whilstthe missile is being propelled such as by its rocket or jet propulsionsystem.

The array of barrel assemblies may be arranged adjacent the leading endor the trailing end of the missile for effecting changes in attitude ofthe missile or medially for displacing laterally displacing the missile.Alternatively the directional control system may include an array ofbarrel assemblies adjacent both leading and trailing ends of themissile.

The array of barrel assemblies may fire a projectile in a directionhaving a longitudinal component in order to provide a consequentaddition to the kinetic energy of the missile or a component in adirection tangential to the longitudinal axis of the missile in order toimpart or change missile rotation about its longitudinal axis. Thebarrel assembly may fire across flight surfaces such as a wing to inducea further steering effect to the missile. Alternatively, the barrelassemblies may extend through the aerofoil surfaces so as to fire inboth directions. This may add structural strength to the aerodynamicdesign.

If desired, a separate array or opposing arrays of barrel assemblies maybe provided to control missile rotation about the longitudinal axis ofthe missile. The configuration of the arrays may include opposing pairsof barrel assemblies which are fired simultaneously to effect changes inrotation about the longitudinal axis of the missile only. Theprojectiles may be selectively actuated before and/or after firingprojectiles from the directional control system to negate or utilize theeffects on the missile of such rotation about its longitudinal axis.

In a preferred embodiment of the invention the directional controlsystem includes a leading array of barrel assemblies disposed about thefront end of the missile and from each of which a projectile may beselectively fired in a radial direction relative to the longitudinalaxis of the missile and a trailing array of barrel assemblies about therear which may be selectively fired in a direction having a radialcomponent and a rearward component.

In certain embodiments of the present invention all the energy requiredto change attitude and the flight direction may be provided by thefiring of projectiles from the barrel assemblies.

In certain applications a plurality of missiles of the present inventionmay be transported in a housing mounted on a rocket, jet or othertransport to be released or fired at a target. For example missiles ofthe present invention may be housed in a directionally controlledmissile such as that employed to defend against incoming missiles. Suchmissiles may themselves incorporate a divert propulsion system of thetype described in the present application. For convenience we will referto missiles for transporting missiles of the present invention astransport missiles although it will be understood that the transportmissiles may themselves impact with the target.

Incoming high altitude ballistic missiles may carry up to 100 warheads,90% of which may be decoy warheads, and on sensing the approach of aantimissile missile deploy its payload of warheads making the task ofdestroying the threat many fold more difficult. A transport missilecarrying a multiplicity of missiles of the present invention may deployor fire the missiles at the individual warheads. The missiles of thepresent invention may be directionally controlled to impact with theirtargets by a divert propulsion system whereby projectiles are fired fromthe array of barrel assemblies. The high rates of fire make this divertpropulsion system viable.

For example a number of missiles may be assigned to each warhead and itsdirection controlled by an advanced tracking and coordination system onthe transport missile that is in communication with a divert propulsioncontrol on each missile. The divert propulsion control on each missilemay then simply activate the firing of the projectiles of selected theprojectiles to be fired in order to attain the desired correction totrajectory of the missile in response to instructions from the advancedtracking and coordination system on the transport missile.

Advantageously the present invention may also provide a directionalcontrol system, which will maintain or increase the kinetic energy ofthe missile at impact with the target. The defensive missile head mayadvantageously be turned side on just before predicted impact toincrease the frontal area, and therefore increasing the killprobability.

In another aspect this invention resides broadly in a method ofcontrolling the direction of a missile including selectively firing oneor more projectiles from an array of barrel assemblies disposed on saidmissile wherein each barrel assembly of said array of barrel assemblieshaving a plurality of projectiles axially disposed within a barrel,which projectiles are associated with discrete propellant charges forpropelling said projectiles sequentially from the barrel, wherein saidarray of barrel assemblies is capable of selectively firing theprojectiles from selected barrels whereby the direction of said missileis controlled by the reactionary force generated by said firing ofprojectiles.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that this invention may be more readily understood and put intopractical effect reference will now be made to the accompanying drawingswhich illustrate a typical application of this invention, wherein:

FIG. 1 is a side view of a missile according to one aspect of thisinvention;

FIG. 2 is a sectional end view through the forward array of barrelassemblies in FIG. 1;

FIG. 3 is a longitudinal sectional view through the rear array of barrelassemblies in FIG. 1, and

FIG. 4 illustrates the defence of a tank being attacked by a missile.

DETAILED DESCRIPTION OF THE INVENTION

The rocket powered missile 10 illustrated in FIG. 1 has a plurality ofbarrel assemblies 11 of the type described arranged about the front endportion 12 and forming a leading array 13 of barrel assemblies and aboutthe tail of the missile forming a trailing array 14.

In the leading array 13, as illustrated in FIG. 2, each barrel assembly11 is arranged radially off the longitudinal axis 15 of the missile 10,while the barrel assemblies 11 in the trailing array diverge rearwardlyand outwardly and with their respective barrel axes 16 radiating fromthe axis 15, as illustrated in FIG. 3.

Each barrel assembly 11 contains one to twelve projectiles 17 which maybe fired individually, or as a burst, at a selected rate of fire up to500,000 rounds per second (rps). Each projectile fired will cause areaction in the missile 10 which, if longitudinally displaced from thecentre of gravity (CG) of the missile 10, will deflect the missile 10onto a new course. If a projectile is fired from a selected barrelassembly 11 a of the leading barrel array 13, the reaction will deflectthe nose portion 12 in the opposite direction A, as illustrated in FIG.2 and this will result in the missile assuming a new course.

This action may reduce the total kinetic energy of the missile. Howeverif a projectile is fired from an opposing barrel assembly 11 in thetrailing array 14, not only will the reaction be greater resulting froman applied moment, firing from the trailing array will provide a boostthe kinetic energy of the missile. This effect can be used to advantageafter all steering corrections have been made, by firing as many of theremaining projectiles from the trailing array 14 as is possible justbefore impact so as to further increase the kinetic energy of theattacking missile. The missile may simply rely on impact or be armedwith a warhead.

Referring to FIG. 4 it will be seen that the defending missile 10 isshown at various positions in its controlled path to collision with anincoming missile 20 attacking a tank 21. The defending missile 10initially may have a path, which would take it above an interceptingposition. Thus at location 24, projectiles are fired upwardly from theleading array 13 and downwardly from the trailing array 14 so as todivert its course downward to location 25 where a further correspondingcorrection is performed.

At position 26 an opposing correction is performed to elevate the noseof the missile 10 so as to align it to a near head-on course with theincoming missile 20. Then at the last instant a further nose downcorrection is performed together with any sideways correction to placethe defending missile onto its final collision course with the attackingmissile 20. At that time the remaining rounds in the trailing array 14which may be fired without causing the missile to move out of itscollision path may be fired to increase the kinetic energy of thedefending missile and thus its lethality. At or shortly after impactwith a target any remaining rounds may be fired with a view to causinggreater destruction of the target.

The defending missile 10 may fly a somewhat zigzag course or aground-hugging course to its target so that it is less vulnerable todetection and/or attack.

The above has been given only by way of illustrative example of thisinvention and it is to be understood that all such and othermodifications and variations thereto as would be apparent to personsskilled in the art are deemed to fall within the broad scope and ambitof this invention as is herein set forth.

1. A missile having a directional control system including an array ofbarrel assemblies from which projectiles are selectively fired, eachbarrel assembly having a plurality of projectiles axially disposedwithin a barrel and associated with respective propellant charges forpropelling said projectiles sequentially from the barrel, wherein atleast some of the barrels in the array of barrel assemblies are orientedto provide the respective projectiles with a component of motion alongthe longitudinal axis of the missile.
 2. A missile as in claim 1 whereinat least some of the barrels in the array are oriented to provide therespective projectiles with components of motion both backwards alongthe axis of the missile and sideways away from the axis of the missile.3. A missile as in claim 1 wherein the array includes a ring of barrelassemblies disposed circumferentially around the missile and behind thecenter of gravity of the missile.
 4. A missile as in claim 1 wherein thearray includes two rings of barrel assemblies disposed around themissile one forward and one rearward of the center of gravity of themissile.
 5. A missile as in claim 1 wherein the array includes a ring ofbarrel assemblies disposed circumferentially around the center ofgravity of the missile.
 6. A missile as in claim 1 wherein the arrayincludes one or more groups of barrel assemblies disposed in relation tothe centre of gravity of the missile to alter both the attitude of themissile about the center of gravity and the trajectory of the centre ofgravity.
 7. A missile having a directional control system including anarray of barrel assemblies from which projectiles are selectively fired,each barrel assembly having a plurality of projectiles axially disposedwithin a barrel and associated with respective propellant charges forpropelling said projectiles sequentially from the barrel, wherein atleast some of the barrels in the array are disposed substantiallyforward of the centre of gravity of the missile and others of the arrayare disposed substantially rearwards of the centre of gravity of themissile so that both the attitude and trajectory of the missile arecontrolled by selective firing of the projectiles.
 8. A missile as inclaim 7 wherein barrels in the array are disposed circumferentiallyaround the longitudinal axis of the missile and at least some of thebarrels are oriented radially from the axis.
 9. A missile as in claim 7wherein the barrels disposed rearwards of the center of gravity areoriented at an angle towards the rear of the missile.
 10. A method ofdirectional control of a missile, including: firing projectiles frombarrel assemblies located forward of the center of gravity of themissile, and firing projectiles from barrel assemblies located rearwardof the center of gravity of the missile, wherein the projectiles areselected and fired to alter either or both of the attitude andtrajectory of the missile.
 11. A method as in claim 10 furtherincluding: firing projectiles with a component of motion along thelongitudinal axis of the missile, wherein the projectiles are selectedto alter the kinetic energy of the missile.
 12. A method as in claim 10further including: firing projectiles radially outwards from thelongitudinal axis of the missile to alter the attitude of the missile.